Display color correcting system

Abstract

A display color-correcting system is provided. Color response values are measured that go into the vertices of polyhedra in a cubic color output space of the display. A set of corresponding values for the display is built from intermediate values determined between the measured color response values. The intermediate values are determined by decomposition and interpolation of interpolation volumes in the cubic color output space. Each of the interpolation volumes is the combined volume of a selected polyhedron within the cubic color output space and a predetermined volume of space between the selected polyhedron and the next polyhedron within the cubic color output space. The set of corresponding values is converted into decoupled RGB adjustment values that specify the RGB signals independently for the display to produce corrected colors. The RGB adjustment values are saved into one or more look-up tables.

1. A display color correcting method, comprising:
 determining a plurality of gray calibration values for a plurality of the display's gray intensity levels from black to white, wherein each of the plurality of gray calibration values comprises a red channel correction value, a green channel correction value, and a blue channel correction value; 
 decoupling the red, green, and blue channel correction values for each of the plurality of gray calibration values; and 
 making compensatory color corrections for a display's output based upon the decoupled red, blue, and green channel correction values of the plurality of gray calibration values. 
 
     
     
       2. The method of  claim 1 , wherein decoupling the red, green, and blue channel correction values of each of the plurality of gray calibration values, comprises:
 creating a red channel correction look-up table containing only the red channel correction values; 
 creating a green channel correction look-up table containing only the green channel correction values; and 
 creating a blue channel correction look-up table containing only the blue channel correction values. 
 
     
     
       3. The method of  claim 2  wherein making compensatory color corrections for the display's output, comprises, for each color value of an image displayed by the display:
 adjusting a red channel value of the color value by a corresponding red channel correction value stored in the red channel correction look-up table; 
 adjusting a blue channel value of the color value by a corresponding blue channel correction value stored in the blue channel correction look-up table; and 
 adjusting a green channel value of the color value by a corresponding green channel correction value stored in the green channel correction look-up table. 
 
     
     
       4. The method of  claim 1 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels further comprises:
 providing a first plurality of input color values to the display, wherein the first plurality of input color values correspond to a plurality of vertices of a plurality of cubes within a cubic color space of the display, each cube having two vertices arranged along a gray diagonal of the cubic color space; 
 measuring a response value for each of the plurality of input color values; and 
 determining a first plurality of gray calibration values corresponding to the first plurality of input color values based on the measured response values. 
 
     
     
       5. The method of  claim 4 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels further comprises:
 determining a second plurality of gray calibration values for a second plurality of input color values by interpolating the first plurality of gray calibration values, wherein the second plurality of input color values correspond to points in intermediate volumes of space between adjacent cube pairs of the plurality of cubes within the cubic color space. 
 
     
     
       6. The method of  claim 5  wherein the intermediate volumes are determined by tetrahedral decomposition of adjacent cube pairs of the plurality of cubes. 
     
     
       7. The method of  claim 1 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels further comprises:
 providing a first plurality of input color values to the display, wherein the first plurality of input color values correspond to a plurality of vertices of a plurality of cuboids within a cubic color space of the display, each cuboid having two vertices arranged along an actual gray line within the cubic color space; 
 measuring a response value for each of the plurality of input color values; and 
 determining a first plurality of gray calibration values corresponding to the first plurality of input color values based on the measured response values. 
 
     
     
       8. The method of  claim 7 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels further comprises:
 determining a second plurality of gray calibration values for a second plurality of input color values by interpolating the first plurality of gray calibration values, wherein the second plurality of input color values correspond to points in intermediate volumes of space between adjacent cuboid pairs of the plurality of cuboids within the cubic color space. 
 
     
     
       9. The method of  claim 8  wherein the intermediate volumes are determined by tetrahedral decomposition of adjacent cuboid pairs of the plurality of cuboids. 
     
     
       10. The method of  claim 7  wherein successive vertices of the plurality of cuboids are successively determined based on a gray calibration value determined for a previously determined vertice of a cuboid, wherein an initial vertice corresponds to point (0, 0, 0) in the cubic color space. 
     
     
       11. A display system capable of color correction, comprising:
 a display for displaying color images having a plurality of color values, each of the plurality of color values comprising a red channel value, a green channel value, and a blue channel value; 
 a memory for storing decoupled red, green and blue channel correction values; and 
 a central processing unit (CPU) coupled to the memory and display for making compensatory color corrections for the display's output based upon the decoupled red, blue, and green channel correction values, wherein the red, green and blue channel correction values are determined by determining a plurality of gray calibration values for a plurality of the display's gray intensity levels from black to white, each of the plurality of gray calibration values comprising a corresponding red channel correction value, a corresponding green channel correction value and a corresponding blue channel correction value. 
 
     
     
       12. The system of  claim 11 , wherein the memory comprises:
 a first look-up table containing only the red channel correction values; 
 a second look-up table containing only the green channel correction values; and 
 a third look-up table containing only the blue channel correction values. 
 
     
     
       13. The system of  claim 12  wherein the CPU makes compensatory color corrections for each color value of an image displayed by the display by executing a plurality of steps, comprising:
 adjusting a red channel value of the color value by a corresponding red channel correction value stored in the red channel correction look-up table; 
 adjusting a blue channel value of the color value by a corresponding blue channel correction value stored in the blue channel correction look-up table; and 
 adjusting a green channel value of the color value by a corresponding green channel correction value stored in the green channel correction look-up table. 
 
     
     
       14. The system of  claim 11 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels, to determine the red, green and blue channel correction values stored in the memory, further comprises:
 providing a first plurality of input color values to the display, wherein the first plurality of input color values correspond to a plurality of vertices of a plurality of cubes within a cubic color space of the display, each cube having two vertices arranged along a gray diagonal of the cubic color space; 
 measuring a response value for each of the plurality of input color values; and 
 determining a first plurality of gray calibration values corresponding to the first plurality of input color values based on the measured response values, wherein each of the first plurality of gray calibration values comprises corresponding red, green and blue channel correction values that are stored in the memory. 
 
     
     
       15. The system of  claim 14 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels, to determine the red, green and blue channel correction values stored in the memory, further comprises:
 determining a second plurality of gray calibration values for a second plurality of input color values by interpolating the first plurality of gray calibration values, wherein the second plurality of input color values correspond to points in intermediate volumes of space between adjacent cube pairs of the plurality of cubes within the cubic color space, wherein each of the second plurality of gray calibration values comprises corresponding red, green and blue channel correction values that are stored in the memory. 
 
     
     
       16. The system of  claim 15  wherein the intermediate volumes are determined by tetrahedral decomposition of adjacent cube pairs of the plurality of cubes. 
     
     
       17. The system of  claim 11 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels, to determine the red, green and blue channel correction values stored in the memory, further comprises:
 providing a first plurality of input color values to the display, wherein the first plurality of input color values correspond to a plurality of vertices of a plurality of cuboids within a cubic color space of the display, each cuboid having two vertices arranged along an actual gray line within the cubic color space; 
 measuring a response value for each of the plurality of input color values; and 
 determining a first plurality of gray calibration values corresponding to the first plurality of input color values based on the measured response values, wherein each of the first plurality of gray calibration values comprises corresponding red, green and blue channel correction values that are stored in the memory. 
 
     
     
       18. The system of  claim 17 , wherein determining a plurality of gray calibration values for a plurality of the display's gray intensity levels, to determine the red, green and blue channel correction values stored in the memory, further comprises:
 determining a second plurality of gray calibration values for a second plurality of input color values by interpolating the first plurality of gray calibration values, wherein the second plurality of input color values correspond to points in intermediate volumes of space between adjacent cuboid pairs of the plurality of cuboids within the cubic color space, wherein each of the second plurality of gray calibration values comprises corresponding red, green and blue channel correction values that are stored in the memory. 
 
     
     
       19. The system of  claim 18  wherein the intermediate volumes are determined by tetrahedral decomposition of adjacent cuboid pairs of the plurality of cuboids. 
     
     
       20. The system of  claim 17  wherein successive vertices of the plurality of cuboids are successively determined based on a gray calibration value determined for a previously determined vertice of a cuboid, wherein an initial vertice corresponds to point (0, 0, 0) in the cubic color space. 
     
     
       21. A display color-correcting method for a display capable of outputting a plurality of color values, and wherein each color value outputted by the display comprises a red channel value, a green channel value, and a blue channel value, the method comprising:
 accessing a red channel correction look-up table containing only red channel correction values; 
 making compensatory color corrections for a plurality of color values outputted by the display by referencing the red channel correction look-up table; 
 accessing a green channel correction look-up table containing only green channel correction values; 
 making compensatory color corrections for a plurality of color values outputted by the display by referencing the green channel correction look-up table; 
 accessing a blue channel correction look-up table containing only blue channel correction values; and 
 making compensatory color corrections for a plurality of color values outputted by the display by referencing the blue channel correction look-up table. 
 
     
     
       22. The method of  claim 21 , wherein the red channel correction look-up table, the blue channel correction look-up table, and the green channel correction look-up table are populated by decoupling the red, green, and blue channel values determined from a plurality of gray calibration values corresponding to a plurality of the display's gray intensity levels from black to white. 
     
     
       23. A display system comprising:
 a display; and 
 a central processing unit (CPU), wherein the CPU is configured to correct a plurality of color values outputted by the display, wherein each color value comprises a red channel value, a green channel value, and a blue channel value that may be adjusted, the system further comprising: 
 means for accessing a red channel correction look-up table containing only red channel correction values; 
 means for making compensatory color corrections for a plurality of color values outputted by the display by referencing the red channel correction look-up table; 
 means for accessing a green channel correction look-up table containing only green channel correction values, 
 means for making compensatory color corrections for a plurality of color values outputted by the display by referencing the green channel correction look-up table; 
 means for accessing a blue channel correction look-up table containing only blue channel correction values; and 
 means for making compensatory color corrections for a plurality of color values outputted by the display by referencing the blue channel correction look-up table. 
 
     
     
       24. The system of  claim 23  wherein the red channel correction look-up table, the blue channel correction look-up table, and the green channel correction look-up table are populated by decoupling the red, green, and blue channel correction values determined from a plurality of gray calibration values corresponding to a plurality of the display's gray intensity levels from black to white.